[TheAceOfHearts]

Crunchyroll used to offer a guided reading experience for some of their manga.

You could probably build a tool that tags each panel and attempts to figure out the order, and then have a human editor do a validation pass. If you have enough people reading a series you can probably crowdsource the panel sequence.

[astrange]

Kindle just added one. I find it annoying because I can't remember how to edit the single-panel mode once you get into it.